This blog provides updated forecasts and comments on current weather or other topics

Monday, January 10, 2011

Major Lowland Snowstorm Out, Windstorm-Heavy Rain In

I have to be brief here (I do have a job at the UW!), so a few comments based on the latest runs.

Very little chance of a major lowland snow.

A very good chance of heavy rain and wind.

There will be snow during the initial hours of the event, but will rapidly turning to rain.

Most probable evolution. As the system approach later tomorrow, some locations will see light snow, possibly a few inches, after rush hour. (This times very well for local DOT departments).

Overnight will turn to rain and temps will warm. Wednesday we will see moderate rain over the lowlands and the development of strong winds. VERY strong winds along the coast and over NW Washington. Very heavy snow in the mountains (a few feet!).

Philosophical question for a future blog: with all the uncertainty at 4-7 days out, is my field doing the population a service telling them what might happen?

PS: There are some light snowshowers scattered around today...nothing significant will fall.

79 comments:

"Philosophical question for a future blog: with all the uncertainty at 4-7 days out, is my field doing the population a service telling them what might happen?"

Absolutely. Especially when it's explained how the options might develop, as you do. TV reports that just say that snow may develop aren't that helpful, but discussions of what could happen and why are very much so.

Thanks for taking the time to post the update. I really appreciate reading about what MAY happen and what data is showing us about the forecast. Equally interesting is why the forecast changes. I read your blog to learn about weather and forecasting, not for an up-to-the-minute report. You're very clear about the uncertainty of long-range forecasting.

BTW, you are ahead of the NWS in predicting the high winds. Their Zone forecasts so far don't show any wind greater than 15-20 mph except for 25 possible on the north coast, and the Area Forecast Discussion for 4:00 am only mentions a gale watch on the coast but nothing for the NW interior.

I like it when you tell us what might happen since you're very good at explaining the risks and uncertainties of the forecast. I like hearing about what a small change in a few variables might do to the forecast. Of course many folks just want to know if it will snow or not. They should stick with the TV guys.

I guess the important question about how early in advance to release forecasts of the potentially impactful events depends on how much lead time the area DOT's and utlities need to prepare for such an event. If it is 4+ days, then I would say it is better safe than sorry, but if they can prepare in 1-2 days, then maybe such predictions are less valuable.

Most people know that forecasts over 3 days in the winter time around here are largely variable, but it doesn't keep you from hoping/fearing that such an event will transpire. The local newscasters to a pretty good job of framing such announcements with disclaimers on their tweets, blogs and tv broadcasts.

I have to admit I'm largely disappointed that the original forecast (http://a.yfrog.com/img610/1953/8z6.gif) is not going to happen. As January progresses, how much does our chance of more lowland snow decrease?

At 4-7 days out, forecasting at the rain/snow divide tends to be more hype based entertainment than anything of utility. What is really important is a good forecast the day before so that we can prepare while there is still time.

Yes you are doing a helpful thing. I drive people to their medical appts thru a nonprofit org and I can refuse a job (given out 2 days before) if the driving conditions are in doubt and someone with a big vehicle or SUV can drive the client.

Given your philosophical question, I think it is your profession's duty to point out when models are suggesting that there may be a major event that far out so that people who need to plan for it can do so. However, I think that a special weather statement like one that was issued on Friday or Saturday (I forget which) is probably unwarrented. If it looks like it's going to happen two days out (with more certainty) that should give the average person plenty of time to prepare. How you show that in the forecast discussion and keep the media from going wild about it is another issue though that I don't have an answer for.

As a high school math teacher who LOVES snow days even more than the students, I have to say I was a little more than crushed by the roller coaster this past week. I really wanted a "Snowpocalypse" :). That said, I understand that it is all about probability. Thanks for your blog and for keeping us grounded in reality.

I'm not sure if long-range forecasts benefit "the population" but for those of us hillbillies who live deep in the Cascade foothills, the service is invaluable. For example, because of this recent snow warning we've waxed our skis, updated our wills, filled all of our spare gas cans, stocked up on dog food, birdseed, and half-and-half (for our morning tea). In 1996, we didn't have a clue about the incoming storm and spent almost ten days entirely cut off. We survived, of course, but it wasn't easy, especially when the generator ran out of gas -- we are far off the Grid, so this was serious.

Two years ago, before we began following your blog, we were surprised by a sudden thaw and heavy rainfall, which brought an unusual flow of surface water down the mountainside above us. This took out our road, scouring it to a depth of over three feet. It took 60 truckloads of rock before we were able to get in or out of here again.

So, the answer, at least for this somewhat unique "population" of forest dwellers, is a resounding YES, please keep those long range forecasts coming, dire or otherwise.

How often do the models 3-5 days out suggest significant weather events that then never happen? Is it all the time? Is it a few times a year?

Does an increasing frequency of significant events predicted but not happening mean that a particular model has to be refined to do a better job excluding them, or is the model doing a good job tracking "near misses" in the weather system that suggest a greater likelihood for significant events to come during the same broader weather pattern, like now, with la niña?

That said - I think you are very responsible in your weather discussions - but some forecasters subscribe to wish-casting in an effort to get page views and ratings. And there lies the problem.

When forecasters say "we're still watching this" and "it's still just a possibility," etc. they are letting the public know to pay attention.

When "news" forecasters lead with "10 inches of snow coming" - stay tuned/read more for details; I think they do everyone a disservice. To be fair we live in a sound-bite/headline world and the public bears some responsibility to read the fine print/hear the full story.

Of course, this is IMHO.

Thanks for your work on this blog - it's great & is very much appreciated.

I absolutely appreciate the work meteorologists do in trying to warn the public of potential events. The key is always to make sure that people are given the correct impression of the confidence level of a given forecast. In not only your blog, but other local weather blogs I read and the NWS forecast, the potential for a large snow event was always stated as something that could happen, but there was little confidence in the forecast yet. As you've often stated, snow is one of the hardest things to predict in advance because of the strong temperature gradient associated with the event -- missing by 100 miles changes the weather drastically for a couple million people. As a non-meteorologist, I appreciate knowing what might happen and getting a good read on what variables influence the forecast so we can see how things evolve. Thanks again!

Cliff, I am new to this blog and just want to thank you for all of your insights. Being a Seattle native and a lover of snow, and all the chaos it brings, I was hoping beyond hope that this latest "epic snow event" would play out as originally shown last week. But I've lived here long enough to know that it's best to wait it out and not get too excited. Thanks again for all that you do.

Yes, to answer your question, you are doing the population a service.I base my answer on one major reason:science in action.

We are seeing an erosion of not just science and math in schools, but also of the understanding of what science even is.

Science is messy, and asks questions that need to be answered over time and with experimentation. your blog is helpful, because you are very quick to point out that predictions are based on models. Models in turn are based on past observation. so in essence you are presenting us with hypotheses, and then going about disproving them or not.

You have very nicely explained your reasonings along the way, both in advance of and after a prediction.

All in all, superficial people may read your blog and respond with " he doesn't know what he's talking about" when you contradict yourself a few days later. But I suspect most people reading your blog recognize and respect science in action.

I discovered your Blog around the Thanksgiving snow we had to end 2010. I wanted to answer your question about whether you provide value to the "masses" at 4-7 days out.

I would rather have the data - than not...and appreciate, as I believe most the populous does, that this is not a perfect science. It is still a science that has drastically improved over the last number of years.

Definitely doing us a service. We were planning an excursion to Seattle from Bellingham to view the Picasso exhibit and the notice helped us decide to avoid the middle of the week. Coulda bought $100 worth of tickets we couldn't use if we couldn't get there.

I'm from the NE and would have no worries driving to Seattle even with 10 inches falling, but the other drivers scare the daylights out of me!

I was told a long time ago that weather forecasts more than 3 days out were kind of for the birds. Since, then, I've been perfectly happy just reading the first 3 days of the "10 day forecast." I think that most were never told that though. It IS misleading to put out a forecast for so many days in advance when the probability of it being correct is so low. (Except for when you explain the various models and theorize about what COULD happen.)

People WANT a 10 day forecast, so that's what they get, right or wrong.

Yes Cliff tilling us " I am telling you something that might happen" vs. the seattle times article of "HEAVY SONW THIS WEEK" then 2 paragraphs in to the article "meh maybe." is less helpful. nature 15 parka of doom 1

I don't know about "the population," but it does me a very direct and practical service.

I live in a rural area, and if it snows here, I get stuck. Sometimes for days. Two years ago I went 17 DAYS before someone in a 4WD with snow tires was finally able to get me out to run errands.

As a more recent example, earlier this week all the forecasts were for "possible lowland snow Sunday, but probably not." So I decided to go to the store Saturday, just in case.

Guess what? It snowed heavily here for about 12 hours, we have 4" of compact snow, and everything has iced up. But I have a pantry full of food, so I'm in good shape!

Personally, I wholeheartedly appreciate forecasts with nuance like "X may happen, but maybe not." It's honest, it's realistic, and it allows me to plan for possible outcomes. Because they come true more often than you'd think!

Thanks for the update. I think you DO do a service by trying to give us longer-range projections. Since my family is in the snow-removal business, we read your blog carefully and faithfully to keep an eye on what's likely to happen. I'd rather be prepared and not have it happen than the other way around!

Making sure WSDOT and SEADOT are ready is definitely something your profession should be doing. Giving them the "This *could*, but we don't know for *sure*" caveat is *also* something you should be doing. I like the fact that you, for one, are doing both.

(The big thing I like about academic weather forecasters as opposed to the other professionals is you can afford to (a) try to *nail* the forecast rather than hedging your bets and (b) *admit* when your not sure, and say why. More interesting reading than the Yellow Parka Brigade.)

re: your philosophical question, I appreciate the insight into what is developing and the reasons that it might or might not materialize. The news outlets were already providing information on the potential storm anyway so it was very nice having some perspective.

I think it's become an expectation among the American public that they're entitled to see a forecast at least 5 days out. I do think most people look at long-term forecasting with a a critical eye though... experience shows that those predictions can be wrong, but I think most people appreciate being able to see the trends.

I also think there are a lot of "enthusiasts" (like many who read this blog) that get excited by "bad" weather and it helps us get through the week to know there is potential for an interesting weather event in our future. In a sense it's almost like gambling - we speculate, and are rewarded some of the time, and skunked at other times.

But I will also say, I have a friend who lives in Manchester, UK who is surprised how much we obsess about weather. His local TV station maybe spends maybe a minute on it. Maybe it's because our weather is more extreme than in the UK? Regardless, we tend to have a preoccupation with weather in this country.

I think that exposing forecasts along with uncertainty to end consumers is doing a valuable service. When weather reports don't expose that uncertainty (as in most weather forecasts on TV, Newspapers, weather.com etc)the end consumer is left confused as the forecasts change rapidly.

I assume that commercial weather reporters don't expose this uncertainty primarily because they think their customers cannot process it. I think that is wrong and they should take the way you expose it as a guide and start exposing a short blurb about their confidence in any forecast. People are accustomed to this in so many other areas (stock market for example) that I expect customers will be happier with the confidence range being made available.

Can you explain how I can calculate the amount of snowfall from the amount of precipitation (like that listed on the Probcast)? For example, the Probcast is predicting 1.79" precipitation for 98068 (Snoqualmie pass) on Wednesday - does that mean 1.79" of snow? Thank you!

Yes 4-7 out day forecasts are useful and other sources will provide them anyway. But, it should be separate from the 1-3 day forecast by some statement of the uncertainty of forecasting past 72 hours.Additionally, the admission of such uncertainty may result in increased resources to improve out day forcasting.

Yes! I love the unfolding drama, and knowing what the active factors are in puzzling out a forecast. Being spoon-fed the "right answer" is no way to learn. And I think most followers of your blog ARE seeking to learn how the weather works around here.

My personal opinion is that you are doing a GREAT service by giving the long-range projection. Perhaps not from a weather forecast perspective, but as you have mentioned a few times, you are not providing a weather forecasting service!

Where you really are doing a fantastic service is in showing how weather forecasting works- what you look for, how weather develops, the uncertainty in the forecasts. When we read forecasts in other places all we get in terms of certainty is an occasional 'chance of' prepended to a statement.

Getting visibility into the actual process, challenges, and uncertainties of a forecast is invaluable- particularly in a situation like this where a high-profile forecast changes.

That also doesn't even cover geeks like me who read your blog not looking so much for a forecast as out of fascination for the weather and how it works and develops.

So to summarize, don't change a thing- the way you are writing and what you are writing about is GREATLY appreciated!

Regarding your question - I work in the field of Business Continuity, which can be summarized as the discipline of "What could possibly go wrong". Part of my responsibilities include monitoring weather events and providing guidance to senior management on appropriate action.

I believe that 4-7 day forecasts are useful, even helpful, with one proviso: Please include a caveat that unless the forecast is within 72 hours, it doesn't really count. I can't tell you how often I repeat that.

Too bad about the lack of big snow potential. I like the way the NWS has handled this whole thing, and not so much the TV forecasters. The NWS was pretty conservative about hyping it, while the TV people were all over it at the first sign of any potential. Social media certainly changes things, with more people having access to specialized info through this blog and others. But I think you can say whatever you want on here, it serves a different function than TV forecasters or the NWS.

Cliff, as to your philosophical question: yes, IF the discussion is clear about POSSIBLE and it is more in the 4-5 day range. The "cry wolf" factor enters if the hype builds without being clear about POSSIBLE outcomes. I thought the Weather Service alerts were balanced and clear. Basically we are talking about sending a "heads up." Seven days out is just too long. Thanks.

I like to hear the 4-7 day out forecast. Living in Leavenworth, I would like to hear some comments on what might happen just over the mountains. And no, I don't drive a pickup with a gun rack -- just a pickup.

This may have been rhetorical, but you asked about the value of 4-7 day predictions and uncertainty. I think it is quite valuable, particularly when traveling and preparing for contingencies. Even if an event fizzles out, I'd rather have some kind of travel insurance or alternate work-remotely forewarning to bosses. Even 2 days notice is a bit short for some of those decisions.

Thinking of the east coast xmas blizzard, $20 in travel insurance would have been a negligible investment compared to the chaos, even if that event fizzled out.

Cliff,I for one am grateful for your 4-7 day-out speculations. I do not use these forecasts as "set in stone" planning information, but general background for me to plan my week. Like someone else said, bring the laptop home each night this week, since we have a "just in case" scenario brewing, whether it turns out to be snow or lots of rain and wind.

You always carefully present that such long-range forecasts are very difficult to nail down exactly and that things could change a lot with each model run; I've heard you say many times. I am glad that you include the caveat each time even though if I thought about it, I could repeat it word-for-word (I've been reading you for over three years now)... you never know who has just discovered you and needs to understand how long-range forecasts can change.

We had graupel again this morning at 210' elevation just west of Lake Sammamish in the Phantom Lake neighborhood of Bellevue. Good times. Even my 10-year old knows what it's called now, thanks to you. Her science-minded 5th-grade teacher at Bennett Elementary was glad that she shared that with him and insisted that she tell the class about it, explaining how graupel forms and how it's different from hail. When she finished telling the class what she knew, her teacher told her it was great that she reads this blog... he's a regular reader too. You ARE making a difference in science education, even if those students aren't sitting in your lecture hall! :-)

In looking at some of the models you presented in the last post, it doesn't look like it will be too major of a wind event in the central sound. At least going by the pressure gradients on the (now several hours old) models. Is there a firmer idea of what the wind speeds should be in the greater Seattle area?

Regarding your philosophical question...I think it depends on who is receiving it. I appreciate the heads up and can put it in the context in which these warnings are given, factoring in the uncertainties. Others that I talk to are chalking it up to media hype, and the weather service "getting it wrong again". Not sure you can please everyone.

Cliff,I think informing people of probable events 3-5 days out is great, and then modifying those as the weather approaches.

I think the problem occurs when TV newscasters hype it up and then have to retrench. Given the intensity of the initial hype and then the forecast reduction, I think it can leave "waether challenged" people with reduced confidence in weather forecasting science.

If the TV forecasters would stick to 48 hour hype and leave the longer, less confident, forecasts to the weather service and sites like Weather Underground.

Cliff,I think informing people of probable events 3-5 days out is great, and then modifying those as the weather approaches.

I think the problem occurs when TV newscasters hype it up and then have to retrench. Given the intensity of the initial hype and then the forecast reduction, I think it can leave "weather challenged" people with reduced confidence in weather forecasting science.

If the TV forecasters would stick to 48 hour hype and leave the longer, less confident, forecasts to the weather service and sites like Weather Underground, then we'd have the best of both.

Cliff, I was thinking about your philosophical question from today vis-a-vis your really funny post from yesterday, in which you admitted that you, like many of your colleagues, have a professional investment in dramatic weather. I've learned a lot about weather and science in general from reading your book and blog. You, and your colleagues, analyze really complex data sets and representations using the best probabilistic tools at your disposal and you at least come clean on what you don't know. I wish that the meteorologists for the commercial services and broadcast media would be so straightforward about things. Please keep that up!

Well, now I'm officially bummed. I was looking forward to snowpocolypse.

Is it a disservice to tell the populace what the models are showing as a possibility 7 days out? I don't think so. In the case of snow, it gives everyone a chance to make sure their car is ready for it (snow tires, chains, flares, shovel, emergency supplies and a full tank of fuel) or just make other arrangements. If it doesn't happen, at least they are prepared, no harm done.

If on the other hand, we get that information 1-2 days ahead when it is almost guaranteed, it is too late to truly be prepared if you weren't already. 90% of the issues with snow in Seattle is lack or individual preparedness.

For some, knowing that a nominal potential for a severe weather event 4-7 is very valuable in potential planning for it. For others who have less riding on the weather may forget that such forecasting is still short of probable it may just create FUD for them.

The trick I think is educating people that forecasting is a very inexact science and that a 4-7 forecast allows you to make contingent plans for low probability events

Yes - please keep posting advance information - probably the best part of the blog for me is to see how the picture changes as we get closer to an event. You are usually very clear about the certainty/uncertainty of an event.

To answer your question before you blog about it, definitely yes! Please continue to provide advance if nebulous warning, then allow us to watch through your posts as the forecasts firm up and become definitive. Hopefully we all understand weather forecasting is both an art form and a science.

I think the 4-7 day forecasts, however unreliable they might be at times, provide a necessary "heads up" to the public at large. Even if the storm does not materialize, it is a good reminder for people to prepare themselves for what may happen.

I think many of us (myself included) are fascinated at the potential for a historic snowstorm, and seek out clues leading us to figure out when it might occur. I check NWS forecasts, discussions, your blog, the 6-10 and 8-14 day prognostic discussions and try to piece together when the potential might be highest. Of course, we know how quickly things can change when looking at longer-lead forecasting products.

So, in summary, I think the 4-7 day forecasts both serve to inform those who may need the information to plan for the potential weather scenario and those who are casual onlookers. I think forecasters adequately warn the viewer of the chance of error in the forecast, as they did in the case of this snowstorm.

What are the chances or probability that this latest forecast is wrong and we do see a big snow event? or is it possible that it is only the timing of snow vs rain that may be a little off? Just curious as to how reliable these models are.

Thank you so much for your blog. And yes... Your field *is* doing the population a service by informing us of possibility *along with* probability. In either best or worse case scenarios we will be better prepared... start conversations with those that may be less informed and thus our communities are safer.

So thank you. And thank you for your comments about stressing the importance of maintaining objectivity. It must be difficult! :)

Not letting the public know doesn't keep weather geeks like myself from checking model output at NCEP every six hours... and, it seems like the 5-7 day model predictions are usually in the ballpark in terms of general trends (cold vs warm, wet vs dry), it's just the specifics that usually evolve. The errors in this case seem (although incredibly disappointing) like outliers. I briefly thought this might be the start to our January 1950..btw Cliff, do you know what was the global pattern setup for that stretch of fun? Oh the stories my grandparents have to tell about that storm and deep freeze...

Cliff ~ You asked "Philosophical question for a future blog: with all the uncertainty at 4-7 days out, is my field doing the population a service telling them what might happen?"

Your field does do us a service by giving us a "heads up" 4-7 days out. Where it becomes a dis-service is when certain weathercasters on certain channels make too big of a deal out of it. This time around they all blew it out of proportion while trying to squeeze in "the models could change by then". No one heard the part that it wasn't a "for sure" thing because they hyped it up so much.

Other than that I appreciate a heads up on what "could" happen so far out!

I was just told about your blog yesterday. The person who told me about it said that it was the only weather news he trusted with having any accuracy whatsoever... After looking it over I can see he was right!

I would be happy if I could consistently get a reliable range of forecasts for the next 24 hours let along 4-7 days. I knew this week would be interesting because my wife and I read your blog. What I didn’t know was when it was going to be interesting. I was quite suspired to wake up to it snowing in Ballard this morning. As of last night all of my traditional weather sources still said “rain” for today (looking at my phone app it looks like data is provided by iMap and AIRNow). I commute on a motorcycle to work I really need to know if it’s going to snow and how much.

I don’t really want to have to critically evaluate my weather provider. From a consumer point of view I want to believe all providers are fungible. Other than anecdotally comparing day to day performance I don’t have the tools or time necessary to grade them. If I do happen to go to NOAA I don’t always have time to dig into the discussion to get the full range of possibilities.

I believe part of the problem is presentation. My main consumption of weather data is “glace and go” style of applications (phone, computer desktop, bing\google). These formats never show variability or amount of confidence in their forecast. It’s always presented in simple icons and a temperature range.

Generally speaking--- bummer. However, given that we are 4+ days out from the weekend can you tell us the probability of the forecast turning back to snow by the weekend? It seems like there is a blanket forecast for rain over the next week or so but if the snow forecast was so volatile from Sunday-Monday, couldn't the opposite occur? Don't worry, you won't get my hopes up or down. I am just wonderin...

Thanks Cliff and yes, it is a good thing to forecast out even with the uncertainty. For one, it is educational to understand the variables and systems that are used. And two, it gives me a heads up about potential planning needs. So please keep it up!

The general public that would visit a weather blog becomes better educated on the subtleties and influences on weather.

If you start to only speak with absolutes and certainties, it seems like the quick track to being someone who would say things like "I'd grade our snow response a B", w/o considering that everyone is impacted differently -- positively and negatively.

Yes, you are doing the community a service to give us information couched along with the limitations inherent in the forecast.

When the media revvs up the hype machine to drive ratings rather than informing the public, that's a problem. Fortunately, the more often the hype machine gets revved up, the more accustomed the public becomes to seeing parkas as opposed to probabilities.

I'd like to see extended forecasts (beyond 2-3 days) qualified and quantified with a percentage or degree element that specifies a level of uncertainty of the forecast. It's a two edged sword to post extended forecasts where there is a high degree of uncertainty and speculation. Those of us who regularly monitor extended forecasts recognize the fluidity inherent in the process. But the amateurs run with the info as if it had already happened. Since this was posed a philosophical question, just to be precise, my comments pertain universally to the NWS and all forecasts. I think the Cliff Mass blog displays tremendous integrity, ethics, responsibility to the community, and balance. You do an outstanding job, Mr. Mass, of qualifying and of exposing any biases you may have--if enthusiasm for weather phenomena can truly be considered a bias. That said, it would be interesting to look at a month from a probability perspective in terms of temperatures, snowfall amounts, etc. I think that might be an alternative to extended forecasts and could put the probability of certain weather events into some perspective.

Yes, I like the long-range forecasts. I think most people know that weather isn't a certainty, but it's certainly nice to be able to prepare a little. What's worse, to fill the car with gas a few days sooner than necessary, or to run out of gas on I-5 stranded in a storm? I'd rather have a unnecessarily full pantry than an empty one. Keep up the good, science-based work!

I totally love to hear what may happen, how likely you think it is, and why you can't be sure, etc etc etc. Super interesting!

We live on a steep hill and our street is pretty much impassable if there is any snow or ice, so I totally would rather be over prepared. It is no fun to hike up our hill lugging groceries, so it's a treat to do a big grocery shop in advance if there is ANY possibility of snow!

Plus it's fun to think about the possibility of snow, even if it fizzles out. :)

I sure appreciate all your info. It's especially nice to get a little bit of the science of WHY your predictions are what they are. That's what I like. Otherwise I can just check the news channels. But yours is WAY more interesting.

My only suggestion (and I'm just joking here) is that you quit your day job and just do this blog full time. Heh. :)

People are going to hear about the inclement weather through some means. That may be through Accuweather's incredibly inaccurate 15-day forecast, thru Weather.com, or another source such as the NWS AFDs. Also, we all have access to the model solutions, so by not telling you'd just have us guessing more. Since we're not meterologists, we need folks in your field you to interpret the data.

Cliff, I'm glad you asked that question because what I miss in the NWS forecasts here is a more detailed discussion of the weather such as they do on the U of H website for Hawaii. Their 4 to 7 day out forecasts describe the most likely outcome of a set of possibilities. Then they discuss those other possibilities.

Let me put it this way. If we had a reasonably accurate 4-7 day outlook on earthquake risk for an event that could quite possibly happen and affect (even cripple) a large area, I would be on board with that. Would that we had earthquake prediction. I think we could all use some lead time in preparing for an event, no matter what it is, that would affect our daily activities and possibly our health. Then if the event didn't pan out, well, you are stocked up and ready anyway, and that's for next time. There is always a next time. Thank you, Dr. Mass.

Cliff, is it just my wishful thinking, or does the satellite show the low heading straight for the Oregon coast??? The most recent loop of the UW site shows the low due west of the N. Cal. heading ENE. With a strong High to the North and an upper Low to the East is this possible? It seems it would have to go almost due North to hit Vancouver Is. After all the models have been known to be wrong, right? ;)

Figetyknits: The 1.79" of precipitation is referring to how deep the snow (plus any rain) would be if it were all melted down into liquid water -- the "water equivalent." Usually newly fallen snow takes up about 12 times the space (pound for pound) that water does. So, if all 1.79" of water were to fall as snow and not rain, you would be expecting roughly 1-1/2 or 2 *feet* of snow at the pass according to that forecast. (It would be less than that if the snow was wetter/heavier, and more than that if the snow was more dry and powdery.) Hope that helps.

I thought I'd heard that Probcast was sadly out of commission at the moment, though, or at least not regularly maintained? Anyone know more?

“Yes” the 4-7 day out crystal ball weather gazing you provide, with all of your focused professional acumen, as excitingly interwoven as the results may be with uncertainty, is valuable for a gazillion reasons. You explain all the possibilities so thoroughly, that I not only get a front row seat in meteorology 101, without registering, and with my fresh double shot, but the lovely iffiness of all those rogue weather systems roaming unpredictably on the game board, (the varied cast of characters knowledgably introduced by yourself), with potential major consequences teetering, plunks me down next to that huge Weather Roulette table in Vegas, where the Weather Gods amuse themselves by blowing a little action on the ball.

Not only do we gain a smattering of education, mixed in with that edgy sense of iffiness that humanity is at least not running this particular show, but because you are more honest about yourself than major media weather personalities would ever dare to be…we get a bit of an enjoyable inside look at Clifford Mass, who is even occasionally humble, as opposed to the empty calories of media slickness.

Might be late to the party, but I REALLY appreciate your forecasts and predictions and especially your reasons and explanations for changing them. We moved here to the Seattle area 10 years ago. We moved up here east of North Bend 5 years ago and up here, the weather has taken on a different meaning than when we lived in the city.

I am the ultimate weather cynic, but I think it's very important to have the heads up about possible major events. So what if we get our hopes up or freak out a little. So what if we prepare for the worst and it doesn't happen. I would rather know about the possibility, than be taken by total surprise.

I've learned a lot from reading your blog and I think you are fantastic, Dr. Mass!